<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    div{
      width: 100px;
      height: 100px;
      /* 设置浮动 left right none */
      /* float: left; */
      /* float: right; */
    }
    .one{
      background-color: red;
      float: left;
    }
    .two{
      background-color: green;
      float: left;
    }
    .three{
      background-color: blue;
      /* 清除浮动元素的影响 */
      clear: both;
    }
  </style>
</head>
<body>
  <div class="one">one</div>
  <div class="two">two</div>
  <div class="three">three</div>
</body>
</html>